Sweet Dihydroflavonol Rhamnoside from Leaves of Engelhardtia chrysolepis , a Chinese Folk Medicine, Hung-qi

From leaves of Engelhardtia chrysolepis, a Chinese sweet tea, a set of the diastereomers of astilbin (3-O-α-L-rhamonosyl-(2R, 3R)-taxifolin) was isolated together with eucryphin and quercitrin. Of these isomers, 3-O-α-L-rhamnosyl-(2S, 3S)-taxifolin (neoastilbin) was found to taste sweet. This is the first discovery of the sweetness of a dihydroflavonol glycoside.